Scatter plot of canonical variate 1 against canonical variate 2 (Canonical Variate Analysis), showing the shell morphological relationship among Rachis Albers, 1850 (bright blue dots), Rhachistia Connolly, 1925 (grey-blue dots), Chinese Pseudobuliminus spp. (orange dots), Chinese enid species (grey dots) and Sinorachis gen. nov. (pink dots). a, Sinorachis onychinus (Heude), SMF42826; b, S. onychinus, SMF104593; c, S. baihu Wu & Chen, gen. and sp. nov., holotype; d, S. onychinus, SMF42825; e, S. aureus (Heude), based on an image from Heude (1890); f, S. onychinus, SMF42827.